EF Flange-back distance: 44 mmLens length : 27 mmTotal : 71 mmTake 71 mm from 300 mm and you have 229 mm/~23 cm (approx.) from the end of the lens.Not too close to 10 cm, but who brings ruler on a photo outing anyway?

Logged

Trusty 20D, a lighter 200, a nifty fifty, and an old Sigma that won't work stopped down.